This invention relates to the separation of ethylene from a mixture of the same with light olefins by contacting said mixture with a special group of acidic crystalline aluminosilicate zeolites, such as those of the ZSM-5 type in order to selectively convert C.sub.3 and higher olefins into products comprising both gasoline and fuel oil while substantially not affecting the conversion of ethylene. The ethylene can then be recovered by simply flashing it off from the higher boiling product.
There are many processes known in the patent and technical literature, as well as in commercial operation which give a mixture of light hydrocarbons comprising ethylene and higher olefins. Thus, by way of illustration, catalytic cracking processes involving the catalytic cracking of gas oil, as well as thermal cracking processes of light paraffins, naphtha, and gas oils all result in mixtures of ethylene with higher olefins. A more recent process resulting in the production of olefinic mixtures containing ethylene involves the conversion of methanol over a ZSM-5 type zeolite. This process is described in Journal of Catalysis, Vol. 56, pages 169-173 (1979). Methanol conversion over ZSM-5 type zeolites is important in areas of the world that are short of petroleum crudes since methanol is produced from synthesis gas comprising mixtures of hydrogen and carbon oxides which, in turn, is produced by the gasification of natural gas or coal, etc.